The firm leased 1,500 square feet at 149 West 24th Street in Chelsea, and plans to open the space in early January. So far, Ideal Properties hired 16 agents with experience in Manhattan, according to co-founder Aleksandra Scepanovic, who ultimately aims to have 30 agents working out of the Chelsea office.

The foray into Manhattan has been several years in the making, she said. Several of the company’s developer clients have properties in both Brooklyn and Manhattan, and buyers and renters tend to look in both boroughs, she said. “They’re used to working with us [in Brooklyn]. It only makes sense for them to receive the same service,” she said.

The move runs parallel to the trend of Manhattan’s biggest residential firms setting up shop in Kings County, where they take on established local players. Citi Habitats acquired Brooklyn-based aptsandlofts.com in 2015 to gain a foothold in the borough, and Douglas Elliman expanded its presence earlier this year when it scooped up Brooklyn Hearth Realty. And the Corcoran Group has by far the most licensed agents in the borough, according to a recent analysis by The Real Deal.

But in recent months, Brooklyn firms are crossing the East River and fighting for market share in Manhattan. In November, Nooklyn said it was opening an office in Union Square. “In the last decade, we’ve seen corporate brokerages from Manhattan set up shop in Brooklyn, so we feel it’s time to return in kind,” Scepanovic said.

In Manhattan, the share of new rental deals with concessions was 29.6 percent in November, according to the latest market report from Douglas Elliman and Miller Samuel. In Brooklyn, concessions rose to 18.6 percent in the same month.

Ideal Properties was the eighth-largest residential firm on TRD’s most recent ranking of Brooklyn brokerages. According to data from the New York Department of State, it has four offices and 192 licensed agents in the borough — making it larger than well-known firms like Halstead Properties, Keller Williams and Brown Harris Stevens.

In Brooklyn, Ideal Properties has offices in Gowanus, Park Slope, Cobble Hill and Williamsburg, and Scepanovic said the company targeted Chelsea because the neighborhood is still evolving in terms of product type and price.

Once the office is up and running, she envisions adding up to three more outposts. The firm’s bread and butter is rentals between $2,000 and $3,000 a month and sales between $850,000 and $2 million, she said. “Manhattan right now seems to have cooled off. For us, that’s a really good market to be in.”